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Debezium source onnector

The Debezium source connector pulls messages from MySQL or PostgreSQL to Pulsar topics.

Configuration​

The configuration of the Debezium source connector has the following properties.

NameRequiredDefaultDescription
task.classtruenullA source task class that implemented in Debezium.
database.hostnametruenullThe address of a database server.
database.porttruenullThe port number of a database server.
database.usertruenullThe name of a database user that has the required privileges.
database.passwordtruenullThe password for a database user that has the required privileges.
database.server.idtruenullThe connector’s identifier that must be unique within a database cluster and similar to the database’s server-id configuration property.
database.server.nametruenullThe logical name of a database server/cluster, which forms a namespace and it is used in all the names of Kafka topics to which the connector writes, the Kafka Connect schema names, and the namespaces of the corresponding Avro schema when the Avro Connector is used.
database.whitelistfalsenullA list of all databases hosted by this server which is monitored by the connector.

This is optional, and there are other properties for listing databases and tables to include or exclude from monitoring.
key.convertertruenullThe converter provided by Kafka Connect to convert record key.
value.convertertruenullThe converter provided by Kafka Connect to convert record value.
database.historytruenullThe name of the database history class.
database.history.pulsar.topictruenullThe name of the database history topic where the connector writes and recovers DDL statements.

Note: this topic is for internal use only and should not be used by consumers.
database.history.pulsar.service.urltruenullPulsar cluster service URL for history topic.
pulsar.service.urltruenullPulsar cluster service URL.
offset.storage.topictruenullRecord the last committed offsets that the connector successfully completes.

Example of MySQL​

You need to create a configuration file before using the Pulsar Debezium connector.

Configuration​

You can use one of the following methods to create a configuration file.

  • JSON


    {
    "database.hostname": "localhost",
    "database.port": "3306",
    "database.user": "debezium",
    "database.password": "dbz",
    "database.server.id": "184054",
    "database.server.name": "dbserver1",
    "database.whitelist": "inventory",
    "database.history": "org.apache.pulsar.io.debezium.PulsarDatabaseHistory",
    "database.history.pulsar.topic": "history-topic",
    "database.history.pulsar.service.url": "pulsar://127.0.0.1:6650",
    "key.converter": "org.apache.kafka.connect.json.JsonConverter",
    "value.converter": "org.apache.kafka.connect.json.JsonConverter",
    "pulsar.service.url": "pulsar://127.0.0.1:6650",
    "offset.storage.topic": "offset-topic"
    }

  • YAML

    You can create a debezium-mysql-source-config.yaml file and copy the contents below to the debezium-mysql-source-config.yaml file.


    tenant: "public"
    namespace: "default"
    name: "debezium-mysql-source"
    topicName: "debezium-mysql-topic"
    archive: "connectors/pulsar-io-debezium-mysql-2.5.0.nar"
    parallelism: 1

    configs:

    ## config for mysql, docker image: debezium/example-mysql:0.8
    database.hostname: "localhost"
    database.port: "3306"
    database.user: "debezium"
    database.password: "dbz"
    database.server.id: "184054"
    database.server.name: "dbserver1"
    database.whitelist: "inventory"
    database.history: "org.apache.pulsar.io.debezium.PulsarDatabaseHistory"
    database.history.pulsar.topic: "history-topic"
    database.history.pulsar.service.url: "pulsar://127.0.0.1:6650"

    ## KEY_CONVERTER_CLASS_CONFIG, VALUE_CONVERTER_CLASS_CONFIG
    key.converter: "org.apache.kafka.connect.json.JsonConverter"
    value.converter: "org.apache.kafka.connect.json.JsonConverter"

    ## PULSAR_SERVICE_URL_CONFIG
    pulsar.service.url: "pulsar://127.0.0.1:6650"

    ## OFFSET_STORAGE_TOPIC_CONFIG
    offset.storage.topic: "offset-topic"

Usage​

This example shows how to change the data of a MySQL table using the Pulsar Debezium connector.

  1. Start a MySQL server with a database from which Debezium can capture changes.


    $ docker run -it --rm \
    --name mysql \
    -p 3306:3306 \
    -e MYSQL_ROOT_PASSWORD=debezium \
    -e MYSQL_USER=mysqluser \
    -e MYSQL_PASSWORD=mysqlpw debezium/example-mysql:0.8

  2. Start a Pulsar service locally in standalone mode.


    $ bin/pulsar standalone

  3. Start the Pulsar Debezium connector in local run mode using one of the following methods.

    • Use the JSON configuration file as shown previously.

      Make sure the nar file is available at connectors/pulsar-io-debezium-mysql-2.5.0.nar.


      $ bin/pulsar-admin source localrun \
      --archive connectors/pulsar-io-debezium-mysql-2.5.0.nar \
      --name debezium-mysql-source --destination-topic-name debezium-mysql-topic \
      --tenant public \
      --namespace default \
      --source-config '{"database.hostname": "localhost","database.port": "3306","database.user": "debezium","database.password": "dbz","database.server.id": "184054","database.server.name": "dbserver1","database.whitelist": "inventory","database.history": "org.apache.pulsar.io.debezium.PulsarDatabaseHistory","database.history.pulsar.topic": "history-topic","database.history.pulsar.service.url": "pulsar://127.0.0.1:6650","key.converter": "org.apache.kafka.connect.json.JsonConverter","value.converter": "org.apache.kafka.connect.json.JsonConverter","pulsar.service.url": "pulsar://127.0.0.1:6650","offset.storage.topic": "offset-topic"}'

    • Use the YAML configuration file as shown previously.


      $ bin/pulsar-admin source localrun \
      --source-config-file debezium-mysql-source-config.yaml

  4. Subscribe the topic sub-products for the table inventory.products.


    $ bin/pulsar-client consume -s "sub-products" public/default/dbserver1.inventory.products -n 0

  5. Start a MySQL client in docker.


    $ docker run -it --rm \
    --name mysqlterm \
    --link mysql \
    --rm mysql:5.7 sh \
    -c 'exec mysql -h"$MYSQL_PORT_3306_TCP_ADDR" -P"$MYSQL_PORT_3306_TCP_PORT" -uroot -p"$MYSQL_ENV_MYSQL_ROOT_PASSWORD"'

  6. A MySQL client pops out.

    Change the connection mode to mysql_native_password.

    mysql> show variables like "caching_sha2_password_auto_generate_rsa_keys";
    +----------------------------------------------+-------+
    | Variable_name | Value |
    +----------------------------------------------+-------+
    | caching_sha2_password_auto_generate_rsa_keys | ON |
    +----------------------------------------------+-------+

    # If the value of "caching_sha2_password_auto_generate_rsa_keys" is ON, ensure the plugin of mysql.user is "mysql_native_password".
    mysql> SELECT Host, User, plugin from mysql.user where user={user};
    +-----------+------+-----------------------+
    | Host | User | plugin |
    +-----------+------+-----------------------+
    | localhost | root | caching_sha2_password |
    +-----------+------+-----------------------+

    # If the plugin of mysql.user is is "caching_sha2_password", set it to "mysql_native_password".
    alter user '{user}'@'{host}' identified with mysql_native_password by {password};

    # Check the plugin of mysql.user.
    mysql> SELECT Host, User, plugin from mysql.user where user={user};
    +-----------+------+-----------------------+
    | Host | User | plugin |
    +-----------+------+-----------------------+
    | localhost | root | mysql_native_password |
    +-----------+------+-----------------------+

    Use the following commands to change the data of the table products.


    mysql> use inventory;
    mysql> show tables;
    mysql> SELECT * FROM products;
    mysql> UPDATE products SET name='1111111111' WHERE id=101;
    mysql> UPDATE products SET name='1111111111' WHERE id=107;

    In the terminal window of subscribing topic, you can find the data changes have been kept in the sub-products topic.

Example of PostgreSQL​

You need to create a configuration file before using the Pulsar Debezium connector.

Configuration​

You can use one of the following methods to create a configuration file.

  • JSON


    {
    "database.hostname": "localhost",
    "database.port": "5432",
    "database.user": "postgres",
    "database.password": "postgres",
    "database.dbname": "postgres",
    "database.server.name": "dbserver1",
    "schema.whitelist": "inventory",
    "pulsar.service.url": "pulsar://127.0.0.1:6650"
    }

  • YAML

    You can create a debezium-postgres-source-config.yaml file and copy the contents below to the debezium-postgres-source-config.yaml file.


    tenant: "public"
    namespace: "default"
    name: "debezium-postgres-source"
    topicName: "debezium-postgres-topic"
    archive: "connectors/pulsar-io-debezium-postgres-2.5.0.nar"
    parallelism: 1

    configs:

    ## config for pg, docker image: debezium/example-postgress:0.8
    database.hostname: "localhost"
    database.port: "5432"
    database.user: "postgres"
    database.password: "postgres"
    database.dbname: "postgres"
    database.server.name: "dbserver1"
    schema.whitelist: "inventory"

    ## PULSAR_SERVICE_URL_CONFIG
    pulsar.service.url: "pulsar://127.0.0.1:6650"

Usage​

This example shows how to change the data of a PostgreSQL table using the Pulsar Debezium connector.

  1. Start a PostgreSQL server with a database from which Debezium can capture changes.


    $ docker pull debezium/example-postgres:0.8
    $ docker run -d -it --rm --name pulsar-postgresql -p 5432:5432 debezium/example-postgres:0.8

  2. Start a Pulsar service locally in standalone mode.


    $ bin/pulsar standalone

  3. Start the Pulsar Debezium connector in local run mode using one of the following methods.

    • Use the JSON configuration file as shown previously.

      Make sure the nar file is available at connectors/pulsar-io-debezium-postgres-2.5.0.nar.


      $ bin/pulsar-admin source localrun \
      --archive connectors/pulsar-io-debezium-postgres-2.5.0.nar \
      --name debezium-postgres-source \
      --destination-topic-name debezium-postgres-topic \
      --tenant public \
      --namespace default \
      --source-config '{"database.hostname": "localhost","database.port": "5432","database.user": "postgres","database.password": "postgres","database.dbname": "postgres","database.server.name": "dbserver1","plugin.name": "pgoutput","schema.whitelist": "inventory","pulsar.service.url": "pulsar://127.0.0.1:6650"}'

    • Use the YAML configuration file as shown previously.


      $ bin/pulsar-admin source localrun \
      --source-config-file debezium-postgres-source-config.yaml

  4. Subscribe the topic sub-products for the inventory.products table.


    $ bin/pulsar-client consume -s "sub-products" public/default/dbserver1.inventory.products -n 0

  5. Start a PostgreSQL client in docker.


    $ docker exec -it pulsar-postgresql /bin/bash

  6. A PostgreSQL client pops out.

    Use the following commands to change the data of the table products.


    psql -U postgres postgres
    postgres=# \c postgres;
    You are now connected to database "postgres" as user "postgres".
    postgres=# SET search_path TO inventory;
    SET
    postgres=# select * from products;
    id | name | description | weight
    -----+--------------------+---------------------------------------------------------+--------
    102 | car battery | 12V car battery | 8.1
    103 | 12-pack drill bits | 12-pack of drill bits with sizes ranging from #40 to #3 | 0.8
    104 | hammer | 12oz carpenter's hammer | 0.75
    105 | hammer | 14oz carpenter's hammer | 0.875
    106 | hammer | 16oz carpenter's hammer | 1
    107 | rocks | box of assorted rocks | 5.3
    108 | jacket | water resistent black wind breaker | 0.1
    109 | spare tire | 24 inch spare tire | 22.2
    101 | 1111111111 | Small 2-wheel scooter | 3.14
    (9 rows)

    postgres=# UPDATE products SET name='1111111111' WHERE id=107;
    UPDATE 1

    In the terminal window of subscribing topic, you can receive the following messages.


    ----- got message -----
    {"schema":{"type":"struct","fields":[{"type":"int32","optional":false,"field":"id"}],"optional":false,"name":"dbserver1.inventory.products.Key"},"payload":{"id":107}}�{"schema":{"type":"struct","fields":[{"type":"struct","fields":[{"type":"int32","optional":false,"field":"id"},{"type":"string","optional":false,"field":"name"},{"type":"string","optional":true,"field":"description"},{"type":"double","optional":true,"field":"weight"}],"optional":true,"name":"dbserver1.inventory.products.Value","field":"before"},{"type":"struct","fields":[{"type":"int32","optional":false,"field":"id"},{"type":"string","optional":false,"field":"name"},{"type":"string","optional":true,"field":"description"},{"type":"double","optional":true,"field":"weight"}],"optional":true,"name":"dbserver1.inventory.products.Value","field":"after"},{"type":"struct","fields":[{"type":"string","optional":true,"field":"version"},{"type":"string","optional":true,"field":"connector"},{"type":"string","optional":false,"field":"name"},{"type":"string","optional":false,"field":"db"},{"type":"int64","optional":true,"field":"ts_usec"},{"type":"int64","optional":true,"field":"txId"},{"type":"int64","optional":true,"field":"lsn"},{"type":"string","optional":true,"field":"schema"},{"type":"string","optional":true,"field":"table"},{"type":"boolean","optional":true,"default":false,"field":"snapshot"},{"type":"boolean","optional":true,"field":"last_snapshot_record"}],"optional":false,"name":"io.debezium.connector.postgresql.Source","field":"source"},{"type":"string","optional":false,"field":"op"},{"type":"int64","optional":true,"field":"ts_ms"}],"optional":false,"name":"dbserver1.inventory.products.Envelope"},"payload":{"before":{"id":107,"name":"rocks","description":"box of assorted rocks","weight":5.3},"after":{"id":107,"name":"1111111111","description":"box of assorted rocks","weight":5.3},"source":{"version":"0.9.2.Final","connector":"postgresql","name":"dbserver1","db":"postgres","ts_usec":1559208957661080,"txId":577,"lsn":23862872,"schema":"inventory","table":"products","snapshot":false,"last_snapshot_record":null},"op":"u","ts_ms":1559208957692}}

FAQ​

Debezium postgres connector will hang when create snap​


#18 prio=5 os_prio=31 tid=0x00007fd83096f800 nid=0xa403 waiting on condition [0x000070000f534000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000007ab025a58> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
at java.util.concurrent.LinkedBlockingDeque.putLast(LinkedBlockingDeque.java:396)
at java.util.concurrent.LinkedBlockingDeque.put(LinkedBlockingDeque.java:649)
at io.debezium.connector.base.ChangeEventQueue.enqueue(ChangeEventQueue.java:132)
at io.debezium.connector.postgresql.PostgresConnectorTask$Lambda$203/385424085.accept(Unknown Source)
at io.debezium.connector.postgresql.RecordsSnapshotProducer.sendCurrentRecord(RecordsSnapshotProducer.java:402)
at io.debezium.connector.postgresql.RecordsSnapshotProducer.readTable(RecordsSnapshotProducer.java:321)
at io.debezium.connector.postgresql.RecordsSnapshotProducer.lambda$takeSnapshot$6(RecordsSnapshotProducer.java:226)
at io.debezium.connector.postgresql.RecordsSnapshotProducer$Lambda$240/1347039967.accept(Unknown Source)
at io.debezium.jdbc.JdbcConnection.queryWithBlockingConsumer(JdbcConnection.java:535)
at io.debezium.connector.postgresql.RecordsSnapshotProducer.takeSnapshot(RecordsSnapshotProducer.java:224)
at io.debezium.connector.postgresql.RecordsSnapshotProducer.lambda$start$0(RecordsSnapshotProducer.java:87)
at io.debezium.connector.postgresql.RecordsSnapshotProducer$Lambda$206/589332928.run(Unknown Source)
at java.util.concurrent.CompletableFuture.uniRun(CompletableFuture.java:705)
at java.util.concurrent.CompletableFuture.uniRunStage(CompletableFuture.java:717)
at java.util.concurrent.CompletableFuture.thenRun(CompletableFuture.java:2010)
at io.debezium.connector.postgresql.RecordsSnapshotProducer.start(RecordsSnapshotProducer.java:87)
at io.debezium.connector.postgresql.PostgresConnectorTask.start(PostgresConnectorTask.java:126)
at io.debezium.connector.common.BaseSourceTask.start(BaseSourceTask.java:47)
at org.apache.pulsar.io.kafka.connect.KafkaConnectSource.open(KafkaConnectSource.java:127)
at org.apache.pulsar.io.debezium.DebeziumSource.open(DebeziumSource.java:100)
at org.apache.pulsar.functions.instance.JavaInstanceRunnable.setupInput(JavaInstanceRunnable.java:690)
at org.apache.pulsar.functions.instance.JavaInstanceRunnable.setupJavaInstance(JavaInstanceRunnable.java:200)
at org.apache.pulsar.functions.instance.JavaInstanceRunnable.run(JavaInstanceRunnable.java:230)
at java.lang.Thread.run(Thread.java:748)

If you encounter the above problems in synchronizing data, please refer to this and add the following configuration to the configuration file:


max.queue.size=